Electrical terminal block



June 1, 1965 P. HusKA 3,187,295

ELECTRICAL TERMINAL BLOCK Filed June 1, 1962 ze 5 f INVENTOR.

United States Patent O 3,187,295 ELECTRCAL TERMlNAL BL'GCK Paul Huslia,739 Moreno, Los Angeles, Calif. Filed .lune i, 1962, Ser. No. 199,429 8Claims. (Ci. 339-149) This invention relates to electrical terminalblocks and is particularly concerned with electrically connectingseparate conductors, two or more conductors, in a convenient andfeasible manner.

Terminal blocks are made in varied forms some with metal posts, somewith sockets, and some with clamps, all for receiving and/or securingthe end or ends of one :or more conductors. These blocks arecharacterized by a body of dielectric material that supports theconducting parts, and by means to clamp the conductors in place. Underoperating conditions these blocks and their electrical connections aresubjected to vibrations and severe heat changes, and it is not uncommonfor conductors to become loosened. Needless to say a loose electricalconnection aggravates the vibration and heat problems. Further, exceptby manually testing each conductor for tightness, it is impossible tomake a visual check for proper electrical connections in a usual andordinary terminal block of the type under consideration.

A general object of this invention is to provide clamp means in aterminal block of the type under consideration whereby proper connectionor disconnection can be determined visually at a glance.

An object of this invention is to provide a new and improved twoposition clamp means in a terminal block of the character described. Theclamp means hereinafter disclosed has a visibly released position and ithas a visibly engaged position, and in the latter position the conductoror conductors are clamped in working position.

it is also an object of this invention to provide an inherent tighteningaction whereby the conductor or conductors are pulled into workingposition by the clamping action involved.

'Another object of this invention is to provide a clamping means, asabove set forth, that has a positive action and yet is operable toreceive variations in conductor diameter or cross-section. As a result,variations in crosssection, size and/ or shape does not adversely aifectoperation of the device within certain limits. Y

It is still another object of this invention to provide a positivemechanical motion that is converted into a pressing action, which actionis transmitted through a multiplying means to apply clamping orpressured engagement in connecting electrical conductors.

The various objects and features of this invention will be fullyunderstood from the followingr :detailed description of the typical formandV application thereof, throughout which description reference is madeto the accompanying drawings, in which:

FIG. 1 is a perspective view showing the terminal block on its support,and indicating additional terminal blocks in phantom lines. V

FIG. 2 is an enlarged detailed sectional view taken as indicated by line2-2 on FG. l', showing but half the structure. Y

FGS. 3, 4 and 5 are detailed sectional views taken as indicated by lines3 3, 4 4 and 5-5 on FIG. 2, respectively. 'i

FIG. 6 is a view similar to FlG. 3 and shows a modified form of theinvention.

The terminal block B illustrated in the drawings is adapted to be usedin multiples and said multiplicity of block-s assembled on a supportingchannel C. The blocks B are therefore modularly formed, a typical blockE being shown as having, generally, iiat opposite sides lll,

a top-ll, a bottom i2, and dat opposite ends 13. The

ice

bottom and top are essentially iiat and parallel, withl conductoropenings 14 entering into the sides 10 at opposite sides of the block B.The ends 13 are adapted to engage dat against the next adjacent block B.v

The channel C is an elongate support adapted tocarry a multiplicity ofblock B in side by side relationship, with their ends 13 engaged witheach other. As shown, the channel C opens upwardly, having a dat bottom15 and opposite parallel side rails 16 with coplanar upperV edges 17.The rails 16 are spaced apart a distance about equal to the width of theblocks B.

The terminal block B is characterized by a mounting means M underlyingthe block for engagement with the channel C. As shown, 4the means M Visoperable to attach and detach the block B to and from the channel C. Inthe preferred form, the means M involves opposite shoulder 18 for seatedengagement on the opposite edges l?, said shoulders being stepped so asto have centering engagement with the channel C. In practice, the blockB has a depending boss 19 that extends between the shoulders l, engagingbetween the side rails 16. Further, and in order to retain the block Bin a working position, a bail 2G is provided at each side of the blockto lock it on to the channel. The bail is shown as a spring biaseddetent latch involving a leaf spring projecting from the block B andwith a hook releasably-engageable under the channel. lt will be apparenthow the bail can be manually deiiected to release when so desired.

ln accordance with the invention the block B is made of a dielectricmaterial, preferably molded in two half shells, as shown. Thus, the twoshells can be assembled over the working components of the structurewhich involves, generally, anoperator A, a pressure generating means D,a pressure multiplying means E, a clamp F, and a contact G.

The operator A is exposed at the top and side of the block B for manualoperation and for visual observation. As shown, the block B is two sidedwith complete and identical conductor connecting mechanisms at each ofthe opposite sides thereof, a description of one being sufficient forboth. In order for the convenienceV of inserting a conductor into place,the opening 14 is upwardly and outwardly inclined and in which case theoperator A is disposed above and parallel with said opening, or at thesame angle of inclination and exposed at the top-side corner of theblock B.

slots Z2 are the said operators in pressure exerting positions, aslaterdescribed. When in angular positions other than said horizontalpositions, the said operators are released. y I

As shown, the operator A has a cylindrical body 23 underlying the headZ1 -to turn on the inclined axis', above referred to. The body 23 is acam'element, a barrel-cam, with a pair of 4diametrically opposite camfaces Z2.- of equal helical pitch. The faces Mare formed as by helicallyslotting the cylindrical body 23, each through 2/3 (appnoximately) ofthe circumference and suitably inclined as shown. In practice, there isaland or detent 2.5 Vat the .top Vend of Aeach cam face 24. Intertheoperator A in working position.

rlhe pressure generating means D is provided to apply i' pressure underVcontrolY ofthe operator A for use by the liatented June l, 1965 Areadily determined whether ornot a good s means E in Vmultiplying andexerting said pressure to the clamp F. The operator A and part of themeans D occupy a bore 27 formed in the block B on said inclined Iaxis.'I'he operator A is rotatably retained in Working position by the groove26, above described. As is shown, the means D involves a resilient link2-8 that extends between the loperator A and pressure multiplying meansE, to operate both in compression and in tension. "Ighe link 2-8 canvary in form and is shown as compr1s1ng la pair of bowed legs 29 toext-end4 longitudinally of the axis of Vbore 27, there being atransverse pivot 30 joining the legs where connection is made to themeans E, and there being a trnnnion 31 projecting from each leg whereconnection is, made to the operator A.` It Vwill be apparent that thebowed legs will straighten when the link 28 is put under tension,thereby establishing spring tension.

The pressure multiplying means E is provided to transfer the springtension from means yD t-o the clamp F, and reversely to retract theclampY F. In accordance with the invention the means E is a lever means,preferably comprising a pair of toggles 3:5 and 36. The upper .toggle 35is piVota-lly carried by the block B by a pin 37, while the lowertogglev 36 is pivotally coupled to the'clarnp F by a pin 3S. Thetransverse pivot 30 of the link 28 couples the overlapping ends of thetoggl-es 35 and 36 so that shifting of the link causes articulation ofthe toggles, to angularly `relate them or to straighten them. Thus, theclamp F is raised or lowered,

and when lowered the pressure applied by the link 28Y is augmented Vasthe toggles rea-ch a straightened condition.

With' the structure thus far described the trunnionsV 31 are operativelyengaged in the helically slotted barrelf cam body 23 to be movedthereby. It will be apparent that the operator A actuates the link 28reciprocally between a relaxedV or compressive condition and an actuatedor tensioned condition. In practice, the shells of the block B aregrooved at 27' in order to guide the vlegs 29, whereby turning Vot' theoperator A effects longitudinal movement of the link 28.

The clamp F is provided to be yieldingly urged into pressured engagementwith the conduct-ors K `and is preferably a body 40 made up ofYdielectric material, like the block B, having an' inclined clamp face41. In accordance withv the invention the clamp body 40 is guidedvertically by vertically disposed chamber walls 42 in the block B,withthe pin 3S centrally located at the top of` the body 46. The face/41is parallel with the inclination of the contact G which occupies thelower side of the opening 14, to oppose the said contact. As a resultof` this inclination withvr respect to the direction of movementy of theclamp F, there is an inward and down- Ward pinching of the conductors Kwhen iinal` pressure is appliedby the clamp F. Further, the said' finalpressure is applied in a direction nor-mal to the disposition of theinclined contact G. Y

The contact G1 isa body of conducting material, and in practice theclamp face 4:1 and cont-act G areboth concave, or the like, for thewedging of a plurality of conductors K therebetweem: as shown. Thecontacts G at opposite sides of the block B are continuations of each'other, being joined Vby a transversely extending connec-V tor bar45integrally formed therewith. In accordance with `good practice, la testpost 46 is provided that connects with the bar 45y and extends upwardlyvto the top l1=1 of the block B where itis protected within a recess 47.`By use of a probe in touching the post 46 it can be electricalconnection is made. Y' Y, Y

In FIG. 67a second Yformfof invention'is shown wherein the operator A'and pressure generating means D' are modied., This form ofthe inventionemploys a differentY type of spring means in the means D and a,

different form of cam means in the operator A'. As shown, the springmeans is of helical form and `is cooperatively related to and engagedwith or in a screw formed Within the body of the operator A'. Theoperator A has an intern-al thread 50 threadedly receiving thehelicalcoil 5l of the link 2S. The extended end of the spring link 28carries a transverse pivot 30' that prevents turning of the spring 'andwhich operates the toggles 3S and 35 as above described. It will beapparent that the lin-k 28 reciprocates upon turning of the operator A',and limited tu-rning of said operator can be accomplished by providing ablind or abrupt end to the thread 5t) in the operator that receives thehelical spring coil. Also, limited opening action ofthe toggles willprevent disengagement of the link 28 from the operator A.

From the foregoing the operation of the instant terminal block will beapparent. Not only are the conductors disposed'at a convenient angle forease of installation, but the clamping and/ or release action isevidently apparent from a simple visual scanning of the many opereatorsYA that may be involved. When the slots ofv the operato-rs are angularlydisposed, the clamps F are retracted with a positive withdrawing action.When the slots of the operators are aligned, horizontally, the clamps Fare yieldingly urged into pressure engagement with the conductor-sunderlying the clamps F. It wil-1 be apparent that deformities no matterhow caused, will be compensated for in the variable deiection of thelinks 2.3, while .adequate pressure is maintained by the pressureaugmenting toggles 35 and 35. As a result, vibration and thermalexpansion and contraction do not adversely affect the electricalconnections made by the device.

Having described only a typical preferred form and application of myinvention, I do not wish to be llimited or restricted to the specicdetails herein set forth, but wish to reserve to myself anymodifications or variations that may appear to those skilled inthe artand falll within the scope of the following claims.

Having described my invention, I claim:

1. A terminal block having terminals arranged back to back and disposed,on inclined axes for the reception of upwardly inclined electricalconductors and includingz' (a) a body having `a pair of oppositelyinclined openings therein for the reception of oppositely inclinedelectrical conductors,

(b) la pair of oppositely disposed manually actuable Y operators at theexterior of the body and each on fan axisY parallel with one of saidopenings,

(c) a pair of clamps carried by the body and each operable in one ofsaidopenings therein normal to and to engage the said conductorsrespectively,

(d) and means coupling the respective operators and clamps, to 'move theclamps into and out of engage- Y ment with the conductors.

2. .A terminal block having terminals arranged back to back and disposedVon inclined axes for the reception'of upwardly inclined electricalconductors and including:

(a) a body having a pair of oppositely inclined openings therein'for thereception of oppositely inclinedl electrical conductors,` Y v (b) a pairof: oppositely disposed manually actuable operators at the exterior ofthe body and each on an axis parallel with one of said openings",

(c) apair of clamps carried by the body andv each operableV in one ofsaid openings therein normal toy and to engage the saidconductorsrespectively,

(d) and resilient means couplingthej respective oper-V (b) a manuallyactuable operator at the exterior of the body,

(c) a clamp carried by the body and operable into said opening thereintoV engage the conductors,

(d) a toggle means comprising, an upper toggle pivotally carried to movein the body, and a lower toggle pivotally supporting the clamp,

(e) and a resilient link pivotally joining the upper and lower togglesand yieldingly coupling them to the operator, to move the clamp into andout of engagement with the conductors.

4. A terminal block for the reception of electrical conductors andincluding:

(a) a body having an opening therein for the reception of electricalconductors,

A (b) a rotatable operator with a head accessible at the "f exterior ofthe body and with a cam,

(c) a clamp carried by the body and operable into said opening thereinto engage the conductors,

(d) and a means comprising movable, connected levers carried by the bodyand movably supporting the clamp, and a longitudinally resilient andmovable link engaged with and extending between the cam and said levers,to be moved by the cam and to move the movably supported clamp into andout of engagement with the conductors.

5. A terminal block for the reception of electrical c0nductors andincluding: v

(a) a body having an opening therein for the reception of electricalconductors,

(b) a rotatable operator with a head accessible at the exterior of thebody and with a barrel-cam,

(c) a clamp carried by the body and operable into said opening thereinto engage the conductors,

(d) and a means comprising movable, connected levers carried by the bodyand movably supporting the clamp, and a longitudinally resilient andmovable link with trunnions engaged with the cam and extending betweenthe cam and said levers, to be moved by the cam and to move the movablysupported clamp into and out of engagement with the conductors.

6. A terminal block for the reception of electrical conductors andincluding:

(a) a body having an opening therein for the reception of electricalconductors,

(b) a rotatable operator with a head accessible at the exterior of thebody and with opposite helically formed slots,

(c) a clamp carried by the body and operable into said opening thereinto engage the conductors,

(d) and a means comprising movable, connected levers carried by the bodyand movably supporting the clamp, and a longitudnally'resilient andmovableV llink with oppositely disposed trunnions engaged in i saidopposite helically formed slots and extending between the operator andsaid levers, to be moved by rotation of the cam and to move the movablyE supported clamp into and out of engagement with the conductors. I 7. Aterminal block for the reception of electrlcal conductors and including:

(a) a body having an opening therein for the reception of electricalconductors,

(b) a rotatable operator with a head accessible at the exterior ofthebody and withr a cam,

(c) a clamp carried by the body and operable into said opening thereinto engage the conductors,

(d) a means comprising movable, connected levers carried by the body andmovably supporting the clamp,

(e) and a resilient link extending between the operator and said leversand reciprocated by the cam to move the clamp into and out of yieldingpressured engagement with the conductors.

8. A terminal block for the reception of electrical conductors andincluding:

(a) a body having an opening therein for the reception of an electricalconductors,

(b) a rotatable operator with a head accessible at the exterior of thebody and with opposite helically formed slots,

(c) a clamp carried by the body and operable into said References Citedby the Examiner UNITED STATES PATENTS Re. 24,647 5/59 Logan 339-75701,167 5/02 Dennis '269-201 1,402,104 1/22 Soss. 1,45 3,202 4/ 23Stevens. 1,634,422 7/27 Holmes. 1,669,337 5/28 Iller 339-263 X 1,988,1711/35 Frank et al. 339-274 2,390,574 12/45 Dunham et al 339-272 X2,466,418 4/49 Gunther 339-119 2,796,289 6/57 Tocchetto. 2,957,157 10/60Carter 339-263 X 2,997,686 8/61 Mason 339-149 3,028,577 4/62 Strauss.

3,034,092 5/62 Majewski 339-119 3,037,182 5/62 Myers 339-149 FOREIGNPATENTS 1,078,555 5/54 France.

1,080,146 5/54 France.

211,726 2/24 Great Britain. 108,032 7/43 Sweden.Y 340,536 10/59Switzerland.

JOSEPH D. SEERS, Primary Examiner.

7. A TERMINAL BLOCK FOR THE RECEPTION OF ELECTRICAL CONDUCTORS ANDINCLUDING: (A) A BODY HAVING AN OPENING THEREIN FOR THE RECEPTION OFELECTRICAL CONDUCTORS, (B) A ROTATABLE OPERATOR WITH A HEAD ACCESSIBLEAT THE EXTERIOR OF THE BODY AND WITH A CAM, (C) A CLAMP CARRIED BY THEBODY AND OPERABLE INTO SAID OPENING THEREIN TO ENGAGE THE CONDUCTORS,(D) A MEANS COMPRISING MOVEABLE, CONNECTED LEVERS CARRIED BY THE BODYAND MOVABLY SUPPORTING THE CLAMP, (E) AND A RESILIENT LINK EXTENDINGBETWEEN THE OPERATOR AND SAID LEVERS AND RECIPROCATED BY THE CAM TO MOVETHE CLAMP INTO AND OUT OF YIELDING PRESSURED ENGAGEMENT WITH THECONDUCTORS.